Functionally graded Al-based composite tubes, reinforced by Al–Cr intermetallic particles, were prepared using horizontal centrifugal casting. A liquid Al–Cr alloy containing 1, 3, and 6 wt% chromium was poured into the centrifugally rotating mold. The present study focused on the effectiveness of process parameters, including mold temperature and rotational speed, on the graded profile of in situ formed particles during centrifugal casting of Al–Cr alloys. Detailed microstructure analysis revealed that the Al–Cr intermetallic compounds formed in situ in the Al-matrix, and segregated onto the outer surface of the tube. Identified intermetallic particles were Al₁₁Cr₂ and Al₇Cr, with more accumulation of the former near the outer surface. The impacts of the process parameters on the thickness of the particle segregation region were found to be dependent on the initial Cr content. At higher Cr content, the resulted gradient was steeper. Brinell hardness test showed an increasing trend of hardness corresponding with the increment of the area fraction of the intermetallic particles. The maximum hardness (54 HB) was achieved at the outermost region of the centrifugally cast Al-6wt%Cr composite at a mold temperature of 600 °C and a rotational speed of 1800 rpm.

使用水平离心铸造法制备功能梯度的铝基复合管，并用铝铬合金颗粒增强。将含有1、3和6 wt％铬的液态Al-Cr合金倒入离心旋转模具中。本研究的重点是工艺参数的有效性，包括模具温度和转速，以及在Al-Cr合金离心铸造过程中原位形成的颗粒的梯度分布。详细的微观结构分析表明，Al-Cr金属间化合物在Al基体中原位形成，并分离到管的外表面上。鉴定出的金属间颗粒为Al ₁₁ Cr ₂和Al ₇Cr，前者在外表面附近有更多的堆积。发现工艺参数对颗粒偏析区域的厚度的影响取决于初始Cr含量。在较高的Cr含量下，产生的梯度更陡。布氏硬度试验表明，随着金属间颗粒的面积分数的增加，硬度增加的趋势。在模具温度为600°C和转速为1800 rpm的情况下，在离心铸造的Al-6wt％Cr复合材料的最外层区域获得最大硬度（54 HB）。